Zone air conditioning system



Dec. 16, 1941. J HA|NEs 2,266,029

ZONE AIR CONDITIONING SYSTEM Filed Nov. 11, 1955 3 Sheets-Sheet l D'ISCHARGED HUMIDITY CONTROL RANGE.

Y; Emm r QIQkmEJIeZMeJ Dec. 16, 1941. J. E. HAINES 2,266,029

ZONE AIR CONDITIONING SYSTEM Filed Nov. 11, 1935 I 3 Sheets-Sheet 2 13. 16, 1941. J. E. 'HAINES 2,266,029

ZONE AIR CONDITIONING SYSTEM Filed Nov. 11, 1955 s Sheets-Sheet :s

Patented Dec. 15, 1941 UNKTED STATES FATE T QFFWE azeaozo zom: em connrrroivmc srs'rnnr Application November 11, 1935, Serial No. 49,161

12 Claims.

The present invention relates to an air conditioning system of general utility but deals particularly with a system in which the conditions of the air in a plurality of spaces are individually controlled.

One of the objects of the present invention is the provision of an air conditioning system in which conditioned air is supplied to a plurality of spaces to be controlled, and in which the effect of this conditioned air on each space is controlled by condition responsive means responsive to the condition of each space. Preferably, the arrangement is such that the means responsive to the conditions in all of the spaces cooperate with each other in a manner to maintain the conditions in all of the spaces equal or ina predetermined relation to each other by varying the amounts of conditioned air delivered to all of the spaces.

Another object of the invention is the provision of air conditioning systems of the types set forth above in which the conditioned air supplied to the various spaces is controlled by air condition responsive means which respond to the conditions in all of the spaces, as by being subjected to a mixture of air withdrawn i om all of the spaces. Looking at this phase the invention in another manner, a supply of conditioned air is controlled by the combined conditions in a plurality of spaces to be controlled and this conditioned air is then supplied to the various spaces and is additionally controlled by the conditions in each space.

A further object of the invention is the provision of means to vary the standard of the mixture of air withdrawn from all of a plurality of spaces in accordance with fluctuations in an outdoor condition and individually controlling th conditions in each of the spaces.

Another object of the invention is the provision of a cooling and dehumidifying system for air in which moisture responsive means controls the c cling of the air when the moisture content is too high and in which temperature responsive means either then heats this air or additionally controls the cooling thereof depending" upon whether heating or cooling is then required.

A further object of the invention is the provision of a system for utilizing the heat generated by a refrigeration system for heating air. This phase of theinventionhas particular utility where the refrigeration apparatus cools the air under the control of a moisture responsive means. the heat generated by the refrigerating apparatus then being used to reheat the air under the control of a thermostat if such reheating be necessary or desirable.

Still another object of the invention is the provision of a heating and-cooling system in 5 which cooled air is supplied to a plurality of spaces under the control of damper means controlled by the temperatures of the spaces, together with means to cause the damper means to take predetermined positions during the heating l0 cycle and controlling the ultimate temperature 1 of each space during the heating cycle by a control arrangement which does not operate the cooling cycle damper means.

Another object of the invention is the provision of a heating'system in which heated air is supplied from a main heating device to each of a plurality of spaces, each space being additionally heated, as required, by an auxiliary heating means controlled by the temperature of the particular space which it heats. In the specific emmaintain this delivered air temperature substantially constant or above a predetermined mimmum. The air is then split up and delivered to the various 4 spaces and individual auxiliary heaters are utilized to furnish additional heat to the air delivered to each space under the control of the temperature of such space.

Other objects of the invention include the combination of the various sub-systems set forth above in manners to provide complete air con- 3 ditioning systems for heating, cooling and dehumidifying and also include the detailed arrangements found in the various sub-systems, .and these objects of the invention, as well as others, will be found in the detailed description, the drawings and the claims.

For a more complete understanding of this particular embodiment of the invention, reference may be had to the-following detailed description and the accompanying drawings, in

which: i

Fig. 1 is a schematic showing of the complete system,

Figl 2 is a detailed schematic showing of the manner in which the temperatures of all of the spaces cooperate in controlling the amount of conditioned air delivered thereto, and

Fig. 3 is a detailed schematicshowing of the manner in'which the main supplyof conditioned air is cooled or reheated.

"Referring first to Fig. 1 of the drawings, two

chamber 28.

cool, according to requirements, are indicated at I8 and II. For the purpose of heating and cooling the rooms I8 and M, an air conditioning device I 2 is provided. This device is provided with an inlet duct |3 for the supplying of air thereto and in this embodiment of the invention, this inlet; duct I3 is in communication with the outside atmosphere so that fresh air is supplied to the air conditioning device |2. The air conditioning device I2 is further provided with a fan H for causing the circulation of air therethrough whereupon the air is discharged into a delivery duct |5 that is provided with two branches I6 and H which respectively communicate with the rooms l8 and H. Near the inlet end of the air conditioning device l2, the same is provided with a transverse partition |8 which provides a preheating chamber l8 and a by-pass plied with a heating medium in a manner to be described hereinafter. The proportions of the fresh air which flow through the preheating chamber l8 and over the preheating coil 2| and which flow through the by-pass chamber 28 are determined by a pair of dampers 22 and 23 which are respectively secured to pivoted shafts 24 and 25. These twodampers 22 and 23 are interconnected by a link 26 in such a manner that the damper 23 moves towards open position as the damper 22 moves towards; closed position and vice versa. A crank 21 is secured to the shaft 24 and is connected to a similar crank 28 by means of a link 28. The crank 28 is secured to the main operating shaft 38 of a motor mechanism 3| which is controlled in a manner to be described hereinafter.

The air conditioning device I2 is further provided with a plurality of cooling coils 35, 36 and 31, the flow of cooling fluid through which is respectively controlled by means of electrically operable valves 38, 38 and 48. Also located in the air conditioning device I2, is a second transverse partition 4| which divides the same into a bypass chamber 42 and a reheating chamber 43. Located within the reheating chamber 43 is a reheating coil 44. The reheating. coil 44 forms a part of a mechanical refrigeration system that includes a compressor 45 which is driven by a compressor motor 48. The hot gaseous refrigerant which is delivered from the compressor 45 first flows through the reheating coil 44, the compressor being connected thereto by means of a pipe 41. The discharge end of the reheating coil 44 is connected to a condenser 48 by means of a pipe 48. The condenser 48 is in turn connected to the electrically operable valves 38, 38 and 48 through a distributing head 48. A return pipe 58 connects the discharge end of all of the cooling coils 35, 36 and31 with the compressor 45. From the foregoing, it will be apparent that the hot gaseous refrigerant is first delivered to the reheating coil 44 and thereby acts to add heat to any air which may be passing thereover- This somewhat reduces the temperature of the gaseous refrigerant and it then passes to the condenser 48 which causes a further reduction in the temperatheir respective electrically operable valves 38,

38 and 48.

The proportions of air passing through the bypass chamber 42 and the reheating chamber 43 Located within the preheating I chamber I8 is a preheating coil 2| which is supare determined by a pair of dampers 5| and 52* which are respectively secured to pivoted shafts 53 and 54. These dampers 5| and 52 are interconnected by means of a link 55 in such a mannet that the damper 52 moves towards closed position as the damper 5| moves towards open position and vice versa. A crank 56 is secured to the shaft 53 and in turn is connected to a similar crank 51 by means of a link 58. The link 5] is in turn secured to the main operating shaft 58 of a motor mechanism 68 which is controlled in a manner to be described hereinafter.

The branch duct I6 is provided with a heating coil which may be supplied with any suitable heating medium and the flow of heating medium thereto is controlled by a valve 66. The valve 66 is provided with a valve stem 61 to which a rack 68 is connected. Cooperating with this rack 68 is a pinion 68 which is secured to the main operating shaft 18 of a motor mechanism 1|. This motor mechanism 1| is controlled by a thermostat responsive to the temperature of the room or' space |8. This thermostat includes a pressure responsive member 12 which has one of its ends secured to or mounted upon a suitable support 13.

built up in the bellows 12 upon temperature The control arm 15 cooperates with a changes. control resistance 11, the arrangement being such that the control arm 15 traverses the control resistance 11 upon temperature changes within the room or space |8, ranging from 70 F. to 74 F. The opposite ends of the 'control resistance 11 and the control arm 15 are connected to the motor mechanism 1| by means of wires 18, 18 and 88'. Power is supplied to the motor mechanism 1| by line wires 8|. This thermostat operates to position the motor mechanism 1| in accordance with the position of the control arm 15 in respect to the control resistance 11 wherefore the valve 66 is positioned in a'graduated manner and may assume any position from full closed position to full open position, depending entirely upon the temperature of the roomor space |8.

The branch duct l6 isfurther provided with a damper which is secured to a shaft 86. A crank 81 is secured to the shaft 86 and is connected to a similar crank 88 by means of a connecting link 88. The crank 88 is in turn secured to the main operating shaft 88 of a motor-mechwhich a rack 85 is secured. Cooperating with the rack 85 is a pinion 86 that is carried by the main operating shaft 81 of a motor mechanism 88. The motor mechanism 88 is controlled by a thermostat responsive to the temperature of the room or space II. This thermostat includes a pressure'responsive member in the form of a bellows 88 which has one of its ends secured to variable pressures therein upon changes in the temperature to which it is subjected-and operates to position a bell-crank having an actuating arm IM and a control arm I02. A spring I03 has one of its ends secured to the actuating arm IM and its other end is secured to the support I and,

temperature of the room or space II, ranging from 70 F. to 74 F. The arrangement is such that the valve 93 is positioned in accordance with the position of control arm I02 in respect to its control resistance I04 wherefore the valve 03 is positioned in a graduated manner throughout its range of movement.

The branch duct I1 is further provided with a damper IIO that is secured to a shaft III. A rank II2 is secured to the shaft III and is connected to a similar crank II3 by means of a link. I I4. The crank I I3 is secured to the main operating shaft II5 of a motor mechanisrn l I6.

The motor mechanism H6 is controlled by the sonjoint action of apair of thermostats, one of which is generally indicated at I I1 and responds to the temperature of the room or space I0.

The other thermostat is generally indicated at I I3 and responds to the temperature of the room or space II. The motor mechanism H5 in turn controls the motor mechanism 9i.

Referring to Fig. 2, the manner in which the its other end secured to the support I20. The compensating arm I3I cooperates with a compensating resistance I33. the arrangement being such that the compensating arm I3I completely traverses compensating resistance I33 upon temperature changes ranging from 75 F. to 82 F.

. in the room or space II.

motor mechanism H6 is controlled by the thermostats H1 and H8 and in which the motor mechanism I I6 in turn controls the motor mechanism 0I-will now due set forth in detail. The

thermostat I I1 might be termed th controlling thermostat and includes a pressure responsive member in the form of a bellows I20. This bellows has one of its ends secured to a. suitable support I2I and operates to position a bell-crank comprising an actuating arm I22, a control arm I23, and a corrector arm I24. The bellows I is charged with a suitable volatile fluid so that variable pressures are created therein upon changes in the temperature to which the bellows I20 is subjected and the variable pressures thus created in the bellows I20 are opposed by a spring I which has one of its ends secured to the actuating arm I22 and its other end secured to the support I2I. The control arm I23 cooperates with a control resistance I26 and the corrector arm I24 cooperates with a corrector resistance I21. The arrangement is such that the control arm I23 completely traverses control re-' sistance I26 upon temperature changes in the room or space I0, ranging from 75 F. to 82 F;-

The thermostat II8 might be termeda compensating thermosta and comprises a pressure responsive member in the form of a bellows I20 which has one of its ends secured to a suitable support I29. The bellows I28 operates-to position a bell-crank that includes an actuating arm I30 and a compensating arm I3I. The bellows I20 is charged with volatile fluid so that variable pressures are created therein upon temperature changes and these variable pressures are opposed by a coiled spring I32 which has one of its ends secured to the actuating arm I30, and

The motor mechanism H6 includes a relay which is provided with an armature I35 that is pivoted at I36 and is provided with legs I31 and I38. The armature I35 controls a switch arm I30 that is secured to the armature I35 through the medium of a block of insulating material I 40. The switch arm I30 is adapted to cooperate with a pair of spaced contacts MI and I42, the arrangement being such that switcharm I39 may engage either of these contacts I 41 or I42 or may be disposed intermediate both of them and engaging neither of them. Cooperating with the leg I31 of the armature I35 is a main relay coil I43 and an auxiliary relay coil I64. Similarly, a main relay coil I45 and an auxiliary relay'coil I46'cooperate with the leg I38 of the armature I35.

The switch arm I30 and the cooperating contacts I4I and I42 control the operation of a reversible motor means which is a part of the motor' mec anism H6. The reversible motor means is h rein shown as comprising two separate motors having rotors I50 and I 5| which are secu ed to a common rotor shaft I52. Field windirfi I53 and I50 respectively cooperate with the r ors I50 and I5I. This rotor shaft I52 is connected to the main operating shaft H5 through suitable reduction gearing indicated generally at I55.

- The main relay coils I43 and I 45 are normally equally energized so that the" switch arm I39 is disposed intermediate the contacts MI and I42. For this purpose, these main relay coils I43 and I45 are connected in series across the secondary I56 of a transformer I51, having a high voltage primary I 53. This series circuit is as follows: from one side of secondary I56, wire I59, wire I60, wire I6I, wire I62, main relay coil I43, wire I63, wire I64, main relay coil I45, wire I65, wire I66, wire. I61 and wire I68 to the other side of secondary'l 56.

The relative energizations of the main relay coils I43 and I45 are adapted to be primarily unbalanced by the main controlling thermostat II1. For this purpose, the control resistance I26 is connected in parallel with the series connected main relaycoils I43 and I45. It will be noted that the right-hand end of control resistance I26 is connectedto the junction of wires I65 and I66 and is therefore connected to the lower end of main relay coil I45, by means of wires I63 and I10. Similarly, the left-hand end of control resistance I26 is connected to thejunction of wires I62 and I6I, and is therefore connected to the lower end of main relay coil I43, by wires III and I12. In addition. the center of corrector resistance I21 is connected to the junctionof wires I63 and I64, and is therefore connected intermediate the main relay coils I43 and I45, through is normally in engagement with the contact I14 as shown in Fig. 2.

For the purpose of modifying the action of the thermostat II1 upon the energizations of the main relay coils I43 and I45, the thermostat II8 has its compensating resistance I33 connected in parallel with the control resistance I26 and also in parallel with the series connected relay coils I43 and I45. For this purpose, the right-hand end of compensating resistance I33 is connected to the junction of wires HI and I12 by a wire I88 and the left-hand end of this compensating resistance I33 is connected to the junction of wires I68 and I18 by a wire I8I. In addition, the compensating arm I3I of this thermostat 'I I8 is connected to the junction of wires I63 and I64,

and therefore intermediate the main relay coils I43 and I45, by being connected to the junction balancing potentiometer which comprises a' balancing resistance I85 and a cooperating balancing contact arm I86 which is operated by the main operating shaft II5. The balancing resistance I85 is connected in parallel with the series connected main. relay coils I43 and I45 by having its right-hand end connected to the junction of wires I66 and I61 by a wire I81 and by having itsleft-hand end connected to the Junetion of wires I68 and I58 by a wire I88. In addition, the balancing contact arm I86 is connected to the junction of wires I15 and I11, through a manually operable rheostat I88, by means of wires I88 and HI.

With the parts in the position shown in Fig. 2, the control arm I23 of the thermostat H1 is engaging the center of control resistance I26 and damper II8 is moved towards full open position so as to supply more of the cooled air to the room or space II. Such movement of main operating shaft I I5 also causes movement of balancing contact arm I86 along balancing resistance I85 to-' wards the right-hand end thereof.- Such movement of the balancing contact arm I86 results in an increase in the voltage drop across relay coil I43 in respect to the voltage drop across relay coil I45. When the balancing contact arm I86 isthus moved far enough along the balancing resistance I85, the pull on leg I31 of the armature I35 will become sufficiently great to separate switch arm I38 from contact I42. Immediately this occurs, the auxiliary relay coil I46 and the field winding I53 are deenergized. Deenergization of the auxiliary relay cofl I48 removes some of the pull on leg I38 of armature I35 wherefore switch arm I38 separates more widely from contact I42, thereby insuring a good, clean break between this switch arm and contact. Further rotation of the main operating shaft II5 ceases. of course, upon deenergization of the field winding I53. If there should be a further rise in temperature in the room or space II, the process set out above will be repeated and the damper II6 will move to a position allowing even more of the cooled air to flow to the room or space II.

If, on the other hand, the temperature of the room or space I6 should;drop, then the control arm I23 of the thermostat II1 will move along control resistance I26 towards its right-hand end.

- This movement of the control arm I23 reduces likewise the corrector arm I24 thereof is engaging the center of corrector resistance I21. Also, the compensating arm I 3I of the thermostat H8 is engaging the center of compensating resistance I33. In addition, the balancing contact arm I86 is engaging the center of balancing resistance I85. Under these conditions, the main-relay coils I43 and I45 are equally energized so that switch arm I38 is intermediate contacts I and I42.

Neither of the field windings I53 nor I54 is energized and the main operating shaft H5 is stationary. Under these conditions, the damper III is half open so that there is an intermediate'fiow of air to the room or space I I. Neglecting for a moment the modifying eflect of the thermostat perature increase in the room or& space II has been sufilcient, switch arm I38 will engage c tact I42 whereupon the field winding I53 and the auxiliary relay winding I46, in series, will be energized by a circuit as follows: secondary I56, wire I58, wire I68, wire I85, switch arm I38, contact I42, wire I86, auxiliary relay coil.I46, wire I61, field winding I53, wire I86, and wire I68 to the other side of secondary I56. Energizatio'n of 288, field winding I54, and wire I88 to wire I66 and the other side of secondary I56. Energization of the auxiliary relay coil I44 increases the pull on the'ieg I31 of armature I 35 so as to hold switch arm I38 in firm engagement with contact I. Energization of the field winding I54 results in rotation of main operating shaft 5 in the opposite direction so that damper III is moved towards closed position and balancing contact arm I86 moves along balancing resistance I towards its left-hand end. Such movement of the balancing contact arm I86 operates to increase the voltage drop across relay coil I 45 in respect to the voltage drop across relay coil I43. When the main operating shaft II5 has thus moved sufiiciently, the pull on leg I36 of armature I35 will be sufiicient to disengage switch arm I38 from contact,l4I so as to deenergize the auxiliary relay winding I44 and the field winding I54. Deenergization of the auxiliary relay winding I44 removes the extra force on leg I31 so that switch arm I38 separates widely from contact I. The main operating shaft II5 ceases rotating upon deenergization of the field winding I54 wherefore the parts remain in the new position wherein dampe III has been moved towards closed position decrease'the aceaoae flow of cooled air to the space or room II. If there should be a further-decrease in the temperature of the room or space II, the process above set out will be repeated and the damper IIIl will move still further towards closed position.

The function of the rheostat I89 is to insert resistance between the balancing contact arm I85 and the connection between the main relay coils I43 and I45 so that a relatively small movement of the thermostat I I1 will result in a relatively large movement of the main operating shaft I I5. As a result, this rheostat I89 may be so adjusted that only a small temperature change in the room or space II will be required to cause a complete movement of damper I ID from its full open position to its full closed position. In other words, adjustment of rheostat I85 makes it possible to provide the thermostat II1 with an operating differential which is considerably smaller than its total differential of 75 F. to 82 F. The function of the thermostat IIB is to select that portion of the total range of operation of the thermostat II1 which will be operative to control the main operating shaft 5. In other words, the thermostat H8 shifts the operating point of the thermostat H1.

With the parts in the positions s'nown wherein the compensating arm I31 of the thermostat II8 is engaging the center of compensating resistance I33, 'the'operating rangeof the thermostat II! will be located in the middle of its total range. Now if the temperature of the room or space ID should rise so that compensating arm I3l of the thermostat II8 moves along compensating resistance I33 towards its left-hand end, the voltage drop across main relay coil I45 will be decreased and the voltage drop across main relay coil I43 will be increased. This means that damper 'l I must move towards closed position in order to rebalance the energizations of main relay coils I43 and I45 or else the temperature of the room or space II must rise to bring about a rebalanced condition. On the other hand,if the temperature of the room or space It should fall, the compensating contact arm I3I will move along compensating resistance I33 towards its age drop across relay coil I43 and an increase in the voltage drop across the relay coil I45 so that the damper IIII must either mov towards open position or the temperature of the room or space II must also fall in order to bring about a balanced condition of the energizations of relay coils I43 and I45.

The main operating shaft H5 of the motor mechanism H6 operates a control arm 205 which cooperates with a control resistance 206. The opposite ends of this control resistance 206 and the control arm 265 are connected to the motor mechanism 9| by means of wires 201, 208 and 209. The arrangement is such that control arm 205 completely traverses control resistance 205 when the main operating shaft H5 moves from one of its extreme positions to its other extreme position. This control arm 205 and control resistance 206 operate to position the. motor mechanism III and its main operating shaft 50 in accordance with the position of main operating shaft II5 of the motor mechanism IIS. The arrangement is such however, that as the main operating shaft II5 causes a closing movement of damper III), the main operating shaft 90 causes .an openingmovement of the damper 85.

- right-hand end and cause a decrease in the voltperatures of both rooms or spaces are equal and are intermediate the range of movements of their thermostats as shown in Fig. 2 each of the dampers NHL-and will be half-open so that each of the rooms II and III receive half of the air being delivered by the air conditioning device I2. Now if the temperature of the room or space II should rise somewhat, the damper a will move towards open position as explained above.

Likewise, the damper 85 will move acorresponding amount towards closed position. This means that more of the air will be delivered to the room or space II than will be delivered to the room or space III. While this increase in the air delivery to the roomor space II will tend to reduce its temperature, the decrease in the delivery of air to the room or space III will tend to allow its temperature to increase. Now if the temperature of the room or space Ill does increase, then, as pointed out above, its thermostat I I8 will cause a clos-.

ing movement of the damper H0 and will cause the damper 85 to move towards open position. On the other hand, if the temperature of the room or space II should decrease the opposite action will take place. Again, if the temperature of the room or space I I should remain unchanged but if the temperature of the room or space III should rise, then the damper IIIB will be moved towards closed position and the damper 85 will be moved towards open position. This increased delivery of air to the room or space III should tend to decrease its temperature whereas the decreased delivery of air to the room or space II will probably permit its temperature to rise. If it should rise, then the thermostat H1 will cause an opening movement of damper no and acorresponding closing movement of the damper 85. It will therefore be seen that the two thermostats H1 and Ila-cooperate in the control of the two dampers I it and 85 in a manner to position such dampers so that the temperature of the two rooms or spaces are maintained substantially equal even though such rooms or spaces are under different loadconditions as by having different numbers of people congregated therein.

The function of the resistance I84 is to somewhat minimize the effect of the thermostat 8 as well as to prevent complete short-circuiting' of either of the main relay coils I43 or I45-upon extreme movements of the thermostat I I8 wherefore the thermostat H1 is always in dominating control of this portion of the system The purpose of the corrector resistance I 21, more and more of which is inserted in circuit with the wire I15 upon rise or fall of the temperature of the room or space II above or below a medium point between its total range of operation. is to tend to maintain the operating diflerential of this thermostat II'I substantially the same irrespective of whether this range is in the middle or near one end as a result of changes in the temperature of the room III.

The switch arm I13 is moved from engagement with contact I14, by deenergization of relay coil- IIQ durin'g those periods when heating is desired, in-a manner which will shortly be described. Such separation of switch arm I13 and contact I14 disconnects the corrector resistance coils I43 and I45. Therefore, regardless of the positions of these thermostats, the balancing con 4 adapted to move a switch arm 224 iiito armature 256 which is pivoted at 251 and charge duct 215 from the two spaces I8 and II is utilized during the cooling cycle of the system to control the valves 38, 39 and 48 of the cooling coils 35, 36 and 31. For this purpose, two motorized mechanisms 2" and H8, one of which is controlled by the relative humidity of the air passing through the discharge duct 2|5 and the other of which is controlled by the temperature of such air as modified by the temperature of the provided with two legs 258 and 259. This armature 256 controls a switch arm 268 which is secured to the armature 256 through the medium of a block of insulating material 26 I. The switch arm 268 cooperates with a pair of spaced contacts .262 and 263 which it is adapted to selectively engage, Associated with the leg 258 of the armature 256 is a main relay coil 264 and an auxiliary relay coil 265. In a like manner, a main relay coil 266 and an auxiliary relay coil 261 are associated with the leg 259 of the armature 256. These mainrelay coils 264 and 266 are normally equally energized by being connected inseries across the secondary 268 'of a transformer 269 having a high voltage primary 218. This circuit is as follows: secondary 268, wire 269, wire 218,

outdoor air, operate switching'means-in control of the valves 38, 39 and 48. These switching mechanisms also control the compressor motor 46. The motor mechanism 211 is provided with a main operating shaft 2l9 to which three cams 228, Mind 222 are secured. The cam 228 is provided with an operating portion 223 which is engagement with a contact 225. Similarly, the cam 22! is provided with an operating portion 226 which is adapted to move a switch 221 into engagement with a contact 228. In a like manner, the cam 222. is provided with an operating portion 229 which is adapted to move a switch arm 238 into engagement with a stationary contact 23L Each of these'switches controls the energization of one of the valves 38, 39 and 48 and also controls a circuit to a three-speed starting box 232 by means engagement with th stationary contact 24! Similarly, the cam 2'31 is provided with an operating portion 242 which is arranged to engage a switch arm 243 and move the same into engagement with a stationary contact 244. In a like manner, the cam 238 is provided with an'operating portion 245 which engages a switch arm 246 and moves the same into engagement with a stationary contact 241. Each of these three switches likewise controls a circuit to'one of the valves 38, 39 and 48 and a circuit to the three-speed starting box 232.

Referring now to Fig. 3 of the drawings, the manner in which the main operatingshait 235 of the motor mechanism 2l8 is controlled, as well as the manner in which this main operating shaft 235 in turn controls the motor mechanism 68, will be explained in detail. The motor mechanism 2 l 8 includes'a reversible motor means herein shown in the form of two oppositely acting motors each of which comprises a"rotor and a field winding." Each of'these rotors,-which are designated at 258 and 25l, is secured to a common rotor shaft 252. The associated field windings are indicated at 253. and 254. This rotor shaft 252 is connected to 'the main operating shaft 235 through a suitable reduction gearing generally indicated at 255. The motor mecha nism 2" includes a relay that is provided witil;

, 295 wherefore the center of this corrector resistance 289 is connected intermediate the main wire 21l, wire 212, main relay coil 264, wire 213, wire 214, main relay coil 266, wire 215, wire 216, wire 211, and wire 218 to the other side of secondary 268.

The energizations of these main relay coils 264 and 266 are adapted to be primarily unbalanced by means of a thermostatic control, generally indicated at 219, which responds to the temperature of the air passing through the discharge duct 2l5 wherefore it responds to the average temperature of the air in the two rooms or spaces l8 and II. This thermostat 219 includes a pressure responsive member 288- in the form of a bellows hich has one of its ends secured to a suita -support'28l. This bellows 288 is connec to a controlling bulb 282 by means of a connecting tube 283. As shown in-Fig. 1, the controlling bulb 282 is located in the discharge duct 2 l5. The bellows, bulb and tube are charged with a suitable volatile fluid which generates pressures in the system that are commensurate with the temperature to which the bulb 282 is subjected. The free end of bellows 288 operates to position a bell-crank which includes an actuating arm 284, a control arm 285, and a corrector am 286. A spring 281 opposes the variable pressures in the bellows 288 and has one of its ends secured to the actuating arm 284 and its other end secured to the support 28L The control arm 285 cooperates with a control resistance 288 and the corrector arm 286 cooperates with a corrector resistance 289. The control resistance 288 is connected in parallel with the series-connected main relay coils 264 and 266 by having its left-hand end connected to the junction of wires 21! and 212 by means of wires 298 and 29l while its righthand and is connected to the junction of wires 215 and 216 by wires 292 and 293. The center of corrector resistance 289 is connected to the junction ofwires 213 and 214 by wires 294 and relay coils 264 and 266. 1

The eflect of the main controlling thermostat 219 upon the respective energizations of the main relay coils 264 and 266 is modified by a compensating thermostat generally indicated at 388 which responds to the temperature of the outdoor atmosphere. This thermostat comprises a pressure responsive, member in the form of a bellows 38l which has one of its ends secured to a suitable support 382. The bellows is connected to a controlling bulb 383 by a tube 384. This controlling bulb 383 may be placed out of doors or, as shown in Fig. 1 of the drawings,- it may be conveniently located in the intake or inlet duct 13 of the air conditioning device l2. The free end of. bellows- 38l positions a bell-crank which includes an actuating arm 385 and a control arm 386. The

aaoopae sistance 288, by having its right-hand end connected to the junction of wires 298 and 29! by a wire 369 and its left-hand end connected to the 266,- as well as in parallel with the control reiunction of wires 292 and 293 by a wire m. The

compensating arm 366 is connected to the junction of wires 298 and 295, through a fixed re- I sistance 3, by wires 3l2 and M8.

The energizations of the main relay coils 266 and 266 are adapted to be rebalanced, irrespective of what causes their unbalancing, by means of a balancing potentiometer comprising a balancing resistance 3 and a cooperating balancing contact arm 3l5 which is secured to and positioned by the main operating shaft 235. The balancing resistance 3% is connected in parallel with the series-connected main relay coils 264 and 266 by having its lower end connected to the junction of wires 269 and 218 by a wire M6 and its upper end connected to the junction of wires 216 and 21? by a wire SW. The balancing contact arm 355 is connected to the junction of wires 29B and 295, through a manually operable rheostat 3I8, by wires 3!!! and 326.

The range of the main controlling thermostat 279 is 75 F. to 82 F. so that the control am 285 completely traverses the control resistance 288 upon a temperature change of this amount. The range of the compensating thermostat 390 is such that the compensating arm 366 completely traverses the compensating resistance 388 upon changes in outside temperature, ranging 75 F. to 100 F. With the parts in the position shown, the temperature of the air in the discharge duct M5 is intermediate 75 F. and 82 F. or approxlmately '78 A F. and the temperature of the outside air is intermediate 75 F. and 100 F. or approximately 87 F. Under these conditions, the control arm 285 is engaging the center of control resistance 288 and the compensating arm 386 is engaging the center of compensating resistance 388. The balancing contact arm 3l5 is engaging the center of balancing resistance 3M wherefore the two relay coils 268 and 266 are substantially energized and the. switch arm 266 is intermediate the contacts 262 and 268. With the parts in this position, the main operating shaft 235 isintermediate its extreme positions.

If the temperatureof the air passing through the discharge duct 285 should rise, the control arm 285 of the main-controlling thermostat 2'59 will move along control resistance 288 towards its left-hand end whereby the voltage drop' across main relay coil 266 will be decreased and the voltage drop across the main relay coil 266 will be increased. The armature 256 will therefore be rotated in counter-clockwise direction and switch am 266 will move towards contact 263. When this rise in temperature of the air passing through the discharge duct 255 has been sufficient, switch arm 26Q will engage contact 263 whereupon the auxiliary relay coil 261 and the field winding 253, in series, will be energized as follows: secondary 268, wire 269, wire 2'88, wire 325, switch arm 268, contact iary relay coil 261, wire 327, field winding 253,

wire 328 and wire 218 to the other side of secondary 268. The energization of the auxiliary relay coil 26? exerts an additional attractive force on the leg 258 of armature 256 wherefore the switch arm 268 is held in firm engagement with contact 263. Energization of field winding 253 causes main operating shaft 235 to rotate in a clockwise direction, as viewed from the right, and also causes balancing contact arm M5 to move upwardly along balancing resistance 3. Such movement of the balancing contact arm 3 l 5 lowers the voltage drop across main relay winding 266 and increases the voltage drop across main relay winding 264. When sufficient movement of main operating shaft 235 has taken place, the relay winding 264 exerts suflicient pull on the leg 258 of armature 256 to move switch arm 260 from engagement with contact 263. When this occurs, the circuit through the auxiliary relay winding 26! and through the field winding 253 is interrupted. Deenergization of auxiliary relay winding 26'! removes the additional pull or attractive force on leg 259 of the armature 256 wherefore switch arm 268 separates more widely from contact 263 to insure a good, clean break. Further rotation of main operating shaft 235 ceases, of course, upon deenergization of ,the field winding 253. In this manner, a rise in the temperature of'the mixture of air discharged from the two rooms or spaces i8 and ii causes a rotation of the main operating shaft 235 of the motor mechanism 218 in a clockwise direction, as viewed from the right.

If the temperature of the air passing through the discharge duct 2l5 should fall, then the control arm 285 of the main controlling thermostat 219 will move along control resistance 2861;0- wards its right-hand end which will cause a decrease in the voltage drop across main relay coil 266 and an increase in the voltage drop across themain relay coil 264. The armature 256 will therefore rotate in a clockwise direction and move switch arm 268 towards the contact 262. When'this temperature drop has been sufficient, the switch arm 26!) engages contact 262 whereupon the auxiliary relay coil 265 and the field winding 254, in series, are energized as follows: secondary 268, wire 269; wire 210, wire 325, switch arm 268, contact 262, wire 329, auxiliary relay coil 265, wire 338, field winding 254, wire 328 and wire 218 to the other side of secondary 268. Energization of the auxiliary relay coil 265 exerts an additional pull on leg 258 of the armature 256 wherefore the switch arm 260 is held in firm engagement with contact 262. Energization of the field winding 254 causes rotation of main operating shaft 235 in a counterclockwise direction as viewed from the right, and

. switch arm 268 separates from contact 262. This also causes movement of balancing contact arm BIS downwardly along balancing resistance 3.

This movement of balancing contact arm 3l5 downwardly along balancing resistance 3 tends to increase the voltage drop across main relay coil 266 and decrease the voltage'drop across main relay' coil 264, and, when the main operating shaft 235 has thus rotated sufliclently far,

deenergizes auxiliary relay coil 265 and the field winding 256. The deenergization of auxiliary relay coil 265 removes the additional attractive force on leg 258 of the armature 256 whereupon the' switch arm 260 separates more widely from contact 262. Further rotation of main operating 263, wire326, aumlshaft 235 ceases upon deenergization of field 'duct 2l5 causes a corresponding counter-clockwise rotation of the main operating shaft 235. The manually operable rheostat 3|6 permits the insertion of resistance in circuit with the balancing contact arm 3l5 which in turn causes a larger movement of the main operating shaft 235 to be necessary in order to rebalance the energizations of the main relay windings 264 and 266. By properly adjusting this rh'eostat 3| 8, a relatively small movement of the control arm 265 of the main controlling thermostat 219 will result in a complete movement of the main operating shaft 235 from one of its extreme positions to its other extreme position. In this manner, the operating difierential of this main controlling thermostat 219 can be made and is made considerably less than its total difierential or total range of movement.

The compensating thermostat 366 serves to shift the operating range of the main controlling thermostat 213. For example, if the outdoor temperature should rise so that compensating arm 366 moves along compensating resistance 306 towards its left-hand end, the voltage drop across relay winding 266 is reduced whereas the voltagedrop across the relay winding 264 is increased. As a result, the main control arm 285 must move to the left along controlresistance 266 in order for the main relay windings 264 and 266 to besubstantially equally energized when the main operating shaft 235 is in its center position. In other words, the control point of the main controlling thermostat 213 is raised as the result of a rise in outdoor temperature. The

. reverse is true on a fall in outdoor temperature so that the control point of the main controlling thermostat 216 is lowered as the outdoor temperature falls. As a result, when-the outdoor temperature is at 75 F., the main controlling thermostat will control at approximately 75 F. to cause clockwise movement of main operating shaft 235 to one of its extreme positions upon a slight rise in temperature above 75 and to cause a counter-clockwise movement t erect to its opposite extreme position upona slight fall in temperature below 75 F. Also, when the outdoor temperature is substantially 87 F., as shown in Fig. 3, then the main controlling thermostat 216 will have its control point shifted to substantially 78%" F. as also shown in Fig. 3.

If the outdoor temperature should rise to 100 F.,

then the control point of the main operating thermostat 213 will be shifted to substantially 82 F. v

The resistance 3 which is connected in circuit with the compensating arm 366 of the compensating thermostat 366 not only prevents complete short-circuiting of either of the relay coils 264 and 266 upon extreme movements of the main compensating thermostat 360 but also modifies its efiect to such an extent that the main controlling thermostat 219 will always have dominating control of the energizations of the relays 264 and 266. The corrector resistance 269, a portion of which is placed in circuit with the Corrector arm 266 upon a rise or fall in temperature above or below the 87 /2 F. value, serves to maintain the operating diiferential of the main controll ng thermostat 219 substantially constant even though its control point be shifted back and forth between the 75 F. value and the 82 F. value.

.From the foregoing, it will now be apparent that a slight change in the temperature of the air passing through the discharge duct M5 is suflicient to cause movement of main operating shaft 235 from one of its extreme positions to its other extreme position. The particular point at which this controlling action will take place depends upon the outside temperature, and by reason of the temperature values selected, it will be noted that the differential between the inside and outside temperature is increased as the outdoor temperature rises.

The movements of main operating shaft'235 are utilized to control the motor mechanism 66 which positions the dampers 5| and 52 that in turn determine the proportions of air which will flow through the reheating chamber 43 and the by-pass chamber 42. In order to accomplish this, the main operating shaft 235 positions a control arm 335 which cooperates with a control resistance 336'. The control arm 335 and the control resistance 336 are connected to the motor mechanism 60 by means of wires 331, 338 and 339. The motor mechanism 66 is so positioned corresponding to the position of the control arm 335 in respect to its control resistance 336, and the arrangement is such that the damper 5i is moved from full open position to full closed position and the damper 52 is moved from full closed position to full open position when control arm 335 moves from the lower end of control resistance 336 to its .upper end.

With the main operating shaft 235 in the intermediate position shown, all the cam operated switches associated therewith are open and the control arm 336- is disposed slightly below the lower end of the control resistance 336. Upon slight clockwise movement of main operating shaft 235, as viewed from the right, the operating portion 239 of cam 236 moves switch arm 246 into engagement with contact 2. Upon further movement of main operating shaft 235 in the same direction to a position in which control arm 336 is disposed downwardly at an angle of about45, the operating portion 242 of cam 231 moves switch arm 243 into engagement with contact 244. Upon further clockwise movement of main operating shaft 236 to its one extreme position, the operating portion 245 of cam 236 moves switch arm 246 into engagement with contact 241. Upon return movement of main. operating shaft 235 to its intermediate position in which it is shown, these switches sequentially open.

A slight movement of main operating shaft 235 from its intermediate position shown in a counter-clockwise direction, as'viewed from the right, causes movement of the control arm 336 into engagement with the lower end of control resistance 336. Further movement of main operating shaft 235 in the' same direction progressively moves control arm 335 upwardly along control resistance 336 and all-of this resistance will have been transversed when the main operating shaft 235 reaches its other extreme position.

This movement of control arm 335 operates motor I mechanism 60 to move damper"5l from its full open position to 'it's'full closed position andto move damper 52 from its fullclosed position to its full open position.

From the foregoing, it will be apparent then that half of the'movementof main operating dampers and 52 through the medium of the motor mechanism 60 and the control potentiometer comprised by control arm 335 and control resistance 336.

Returning again to Fig. 1 of the drawings, the motor mechanism 2 I1 is controlled by a relative humidity responsive controller generally in dicated at 345. This comprises a relative humidity responsive element 346 which may take the form of a plurality of strands of human hair, one end of each of which is'secured to a support or bracket 341, whereas the other end of each is secured to a support or bracket 348. The bracket 341 is anchored in any suitable manner and is herein shown as being fastened to the wall of the discharge duct 2|5. The bracket 348 operates a bell-crank by being connected to the actuating arm 349 thereof. A spring 350 operates to keep the humidity responsive element 346 under tension at all times and has one of its ends secured to the actuating arm 349 and its other end secured to a suitable support 35l. The bell-crank also includes a control arm 352 which cooperates with a control resistance 353. The opposite ends of the control resistance 353 and the control arm 352 are all connected to the motor mechanism 2|1 by wires 254, 255 and 256. This humidity responsive controller has a range of from 40% to main operating shaft 2 l9 of the motor mechanism 2" is in an intermediate position. It is thought that it will now be clear that the main operating shaft m or this motor mechanism2|1 is positioned in accordance with the movements of the control arm 352. When the main operating shaft 2|9 is in the mid-position shown, the .switch arm 224 is engaging the contact 225. This main operating shaft 2|9 controls its associated switch arms in the same general manner as does the main operating shaft 235 control its switch arm except that the full movement of main operating shaft 2|9 is used to operate its switches whereas only half of the movement of main operating shaft 235 is used to operate its switches. In other words, with the main operating shaft 2|9 in its extreme position after having rotated in a counter-clockwise direction as viewed from the right, all of the three associated switches are opened. This condition of the parts takes place when the relative humidity is at approximately If the relative humidity now rises slightly,

' midity rises to substantially then the main operating shaft 2|9 has moved to its other extreme position and the operating portion 229 of thecam 222 moves switch arm 230 into engagement with contact 23 I.

The preheating coil 2|, which is located in the A preheating chamber I9, is supplied with any suitable source of heating mediumby means of'a supply pipe 360 which communicates with two branch pipes 36| and 362. These branch supply pipes in turn communicate with the preheating coil 2|. An electrically operable valve 363 controls the flow of heating fluid through the branch I pipe 36| and a similar electrically operable valve 365 controls the flow of heating fluid through the branch pipe 362.

The valve 363 is controlled by an outdoor temperature responsive thermostat that includes a bellows 366 which is secured to a suitable support 361. This bellows is connected to a controlling bulb 368 by a connecting tube 369. The bellows 366 positions a switch carrying arm 310 that supports a mercury switch 31|. A spring 312 connects the switch carrying arm 310 and the support 361 and operates to oppose the variable pressures created within the bellows 366 by the volatile fluid with which the bellows, bulb and connecting tube are charged. The bulb 361 responds to the temperature of the outside air and may be conveniently located in the intake duct |3 as shown in. Fig. l. The setting of this thermostat is such that the mercury switch 31| is in the position shown whenever the outside temperature is at or about 50 F. When in this po-- sition, a closing circuit for the valve 363 is established as follows: line wire 313, mercury switch 3", wire 314, valve 363 and line wire 315. If the outdoor-temperature falls to 50 F. or therebelow, then the mercury switch 31| moves to the position opposite that shown so that the.

mercury thereof is in its right-hand end whereupon a valve opening circuit for the valve 363 is established as follows line wire 313, mercury switch 3", wire 316, valve 363, and line wire 315.

The valve 365 is controlled by a similar thermostat that includes a bellows 380 which is secured to a suitable support 38|. A control bulb 382 is connected to the bellows 380 by means of a tube 383. The bellows 380 positions a switch car-' rying arm 384 whi :h support a mercury switch 385. A spring 386 has one of its ends secured to the switch carrying arm 38 and its other end q secured to the support 38| and serves to oppose the variable pressures built up in the bellows 380 by the volatile fluid with which the bellows and its associated control bulb, as well as the connecting tube are charged. The control bulb 382 of this thermostat likewise responds to outdoor temperature and may be located'in the fresh air inlet duct l3. The adjustment of the thermostat is such that the mercury switch 385 remains in the position shown in Fig. 1 so long as the outdoor temperature is at or above approximately 30 F. When the mercury switch 385 is in such position, a valve closing circuit i established for valve 365 byv a circuit as follows: line wire 386, mercury switch 385, wire 381, valve 365, and line wire 388. Whenever the outdoor temperature falls below 30 F., the mercury switch 385 moves to the opposite position wherein the mercury thereof is in its right-hand end, whereupon a valve opening circuit is established for valve 365 as follows: line wire 386, mercury switch 385, wire 389, valve 365, and line wire 388.

The valves 363 and 365 may be of the same size or may be of different sizes and the temperatures at which these controlling thermostats operate may be varied, all depending upon the particular conditions to be controlled and the locality in which the installation is made.

whatsoever is supplied to the preheating coil 2| as long as the outdoor temperature is ator above 50 F. When the outdoor temperature is between 30 F. and 50 F.,the valve 363 is opened'sothat; an intermediate supply of heating medium is allowed to pass to the preheating coil 2|. When With the values given above, it will be seen that no heating fluid v the outdoor temperature falls below 30 F., then both valves 363 and 365 are opened so that a full supply of heating medium is delivered to the preheating coil 2|.

The motor means 3| which control the positions of the inlet dampers 22 and 23 that in turn determine the proportions of air which will flow through the preheating chamber l9 and the bypass chamber 20, is controlled by a thermostatic mechanism responsive to the temperature of the air passing through the delivery duct l5. This thermostat is generally indicated at 395 and includes a bellows 396 which has one of its ends secured to a support 391. This bellows 396 is connected to a controlling bulb 398 by means of a connecting tube 399. The bellows 396 positions a bell-crank which includes an actuating arm 400, with which the "bellows 396 directly cooperates, and a control arm 40|. A spring 402 has one of its ends secured to the actuating arm 400 and its other end securedto the support 391 and serves to oppose the variable'pressures created in bellows 396 by the volatile fluid with which such bellows, as well as the controlling bulb and connecting tube, are charged. The control arm 40| cooperates with a-contro1 resistance 403. The opposite ends of this control resistance 403 and the control arm 40| are all connected to the motor mechanism 3| by means of wires 404, 405 and 406. The thermostat 395 has a relatively small range and its control arm 40| traverses the associated control resistance 403 on small temperature changes above and below 60 F. When the control arm 40| engagesthe extreme right-hand end of control resistance 403 by reason of a low temperature in the duct l5. the motor mechanism 3| is positioned so that the damper 23 is completely open and the damper 22 is completely closed, so that all of the fresh air being delivered to the air conditioning device l2 must pass over the preheating coil. As the temperature in the duct l rises, so that control arm 4! moves along control resistance 403 towards its left-hand end, thi damper 23 moves toward closed position and the damper 23 moves towards open position to permit part of the air to by-pass around the preheating coil 2 When the temperature of the air in the duct I5 is slightly above 60 F. so that control arm 40| engages the extreme left-hand end of resistance 403, then the motor mechanism positions the dampers 22 and 23 so that the damper 23 is completely closed and the damper 22 is full open. Under these conditions, none of the fresh air entering the air conditioning device l2 passes over the preheating coil 2| and all of it by-passes therearound, going by way of the bypass chamber 20.

In view of the previous detailed description of the manner in which the motor mechanism 6 is controlled by its main controlling thermostat H1 and in view of the similar description in detail of the manner in which the motor mechanism 2|8 is controlled by its main controlling thermostat 219, it is thought that it will now be evident as to how the motor mechanisms, 3|, 60, 1|, 9| 'and 98 are positioned by their respective controllers. However, if it should be desired to have these motors of the mechanical follow-up type instead of the electrically balanced type, reference may be had to the patent to Lewis L. Cunningham granted February 5, 1935, No. 1,989,972. I

Also, it is thought that the detailed description relative the motor mechanisms 6 and 2|8 indicate the manner in which the associated compensating controls vary the action of the main controlling thermostats. However, if desired, reference may be had to the copending application of John E. Haines, Serial No. 38,946, filed September 3, 1935, wherein compensated circuits such as this are disclosed generally, as well as specifically.

The control system of the present invention further includes an outdoor temperature responsive thermostat, generally indicated at 0, which serves to place certain of the apparatus into and out of operation, depending upon whether a cooling cycle or a heating cycle is desired. This thermostat 0 includes a bellows 4 which has one of its ends secured to a suitable support 4|2. The bellows 4 is connected to a controlling bulb M3 by means of a connecting tube 4. Thisbulb 4|3 responds to the temperature of the outside air and may be located in the fresh air inlet duct l3, as shown in Fig. 1. The free end of bellows 4 positions a switch carrying arm 5 which supports a mercury switch 4|6. A spring 4" has one of its ends secured to the switch carrying arm H5 and its other end secured to the support H2 and serves to oppose the variable pressures created in bellows I by reason of the volatile fluid with which it, as well as the controlling bulb 4|3, is charged. This thermostat 4|0 serves to control .the flow of power to the various switches operby line wires 422 and 423, the flow of power fromsuch line wires being controlled by a manually operable switch 424. Line wire 423 leaving the switch 424 has been shown as' grounded at 425 for convenience of illustration.

Operation of the complete system .r

With the parts in the position shown, the outdoor temperature is approximately 87 F., the temperature of each of the rooms or spaces l0 and is approximately 78 F., the temperature of the mixture of air flowing through the dis charge duct 2|5 is approximately 78 F., and the relative humidity thereof is approximately 45%. Since the temperature of the outdoor air is at this relatively high value, both the valves 363 and 365 are closed and no heating fluid is being supplied to the preheating coil 2|. The temperature of the air being delivered by the fan l4 will vary by reason of the control action to be explained hereinafter. "This however, while it causes operation of the motor mechanism 3| to variably position the inlet mixing dampers 22 and 23,.has no eifect upon the operation of the system during the cooling cycle because it makes no diil'erence whether the fresh air passes through the preheating chamber l9 or the bypass chamber 20 since no heating fluid is being supplied to the preheating coil 2|.

Also by reason of this relatively high outdoor temperature, the mercury switch 6 is closed. The manual switch 424 is also closed. As a result, both fan motors 420 and 42| are energized, the relay coil I19 is energized, and power is available to the switches associated with the two motor mechanisms 2" and 2|8. "The circuit for fan motor 420 is as follows: line wire 422, manual switch 424, wire 426, fan motor 420 and ground 425. The circuit for fan motor 42| is as follows: line Wire 422, manual switch 424, wire 421, wire 432, relay coil 119, wire 433, and ground 425.,

The two fans 14 and 216 are therefore operating to cause the passage of air through the air conditioning device 12, to the two rooms or spaces 19 and 11, and out through the discharge air duct 215. Also, since the relay coil 119 is energized, the switch arm 113 is engaging contact 114 so that the two room thermostats 111 and 118 are operative to position the dampers 85 and 119 in a manner to maintain the temperature of both of these rooms equal, as explained in detail in connection with Fig. 2. Y

None of theswitches associated with the motor mechanism 218 is closed but, since the relative humidity is at 45%, the main operating shaft 219 of the motor mechanism 211 is in its intermediate position wherefore switch arm 224 is engaging contact 225. Engagement of these parts establishes an energizing circuit for the electrically operable valve 49 and also establishes a low speed circuit to the three-speed control box 232. This circuit for electrically operable valve 49 and the three-speed control box 232 is as follows: line wire 422, manual switch 424, wire 421, mercury switch 416, wire 431, wire 434, wire 435, switch arm 2'24, contact 225 and wire 436,'at which point the circuit branches, one portion going by way of -wire 443 to the three-speed control box 232 and thence to ground 425 by a wire 444, whereas the other portion goes-by way of wire 431, electrically operable valve 49, wire 438, wire 439 and 449 to ground 425. The compressor motor 46 is therefore being operated at low speed so that it is supplying a small amount of hot gaseous refrigerant to the reheating coil 44 after which it pnses tot-he condenser 48. The liquefied refrigerant then flows to the cooling coil 31 and back to the compressor 45. Although the reheatm, wire at, mercury switch 416, wire m, wire m, wire m, switch arm :21, contact us and wire-451, at which point the circuit branches,

part going by way of wire 452, three-speed control box 232 andwire 444 to ground 425, whereas 6 the other portion goes by way of wire 453, electrically operable valve 39, wire 454, wire 439, and

wire 449 to ground 425. The compressor 45 is ing coil is thus being heated, so long as the temperature of the discharged airin the duct 215 remains unchanged, the motor mechanism 218 will remain in the position shown wherein the control arm 335'is disengaged from the control resistance 336 so that the motor mechanism 69 is positioned to maintain the damper 52 closed and the damper 5| completely open. Therefore, all

.of the air passing through the air conditioning device 12 is by-passed around the reheating coil 44 and receives no heat therefrom. The air pass-- ing over the cooling coil 31 is lowered in temperature in order to provide a dehumidifying action and this air is then delivered to the rooms or spaces 19 and 11 in proportions determined by the positions of dampers ,85 and 118.

Assuming that the relative humidity of the air being discharged from the spaces 19 and 11 rises,

thereupon operated at a greater speed and supplies more refrigerant, part of which now passes through the cooling coil"36,as well as through the cooling coil 31. This additional cooling surface causes a further reduction in the temperature of the air passing through the air conditioning device 12 to remove more moisture therefrom in an effort to check the rising humidity in the "air passing through the discharge duct 215.

If the humidity of this air should increase still further so that control am 352 moves to the right-hand end of control resistance 353, then main operating shaft 219 of the motor mechanism 211 will move to its extreme position, while'moving in a clockwise direction as viewed from the right, whereupon the operating portion 229 of the cam 222 moves switch arm 239 into engagement with contact 231 Engagement of these parts establishes an energizing circuit for the electrically operable valve 38 and establishes a high-speed circuit to the three-speed starting box 232. This circuit is as follows: line wire 422, manual switch 424, wire 421, mercury switch 416, wire 431, wire 434, wire 455, switch arm 239, contact 231, wire 456, and wire 451, at which point the circuit branches, one portion going by way of wire 458 to the three-speed starting box 232 and wire 444 to ground 425, whereas the other portion goes by way of'wire 459, electrically operable valve 38, wire 469 and wire 449 to ground 425. The compressor 45 is nowoperated at high speed and the large quantity of refrigerant thus produced flows through each of the three cooling coils 35, 36 and 31. This will cause an even greater reduction in the temperature of the air passing through the air conditioning device 12 and should restore the relative humidity to a lower value.

Whenever any or all of these cooling 00118 are '.hand end whereupon the main'operating shaft which could result from any number of reasons, I

then the control am 352 of the relative humidity controller 345 will move along control resistance 353 towards its right-hand end and'cause the main operating shaft 219 of the motor mechanism 211 to rotate in a clockwise direction as move switch arm 221 into engagement with concompressor motor 46 through the three speed control box 232. This circuit arrangement is as follows: line wire 422, manual switch 424, wire 235 of the motor mechanism 218 will be rotated in a counter-clockwise direction'as viewed from the right. Suchmovement of the main operating shaft 235 away frdm its intermediate posimechanism 69 will be operated to move damper 52 towards open position and damper 51"towards closed position. Part of the air leaving the coole ing coils is thus diverted, throughthe reheating l chamber 43 and over the reheating coil 44." "I 'hej hot gaseous refrigerant'flowing through re heating coil 44 wiilthereupon raise'th'e tempera ,ture of this portion Qt thecooled air so'as -to I restore theftemperature' of the mixturgfoffain passing out of the'discharge duct 215. Th clower ill the temperatureof air falls below parperature control bulb 282.

ticular operating point of the thermostat 219 for the outdoor conditions prevailing, the more of the cooled air will be passed through the reheating chamber 43 and over the reheating coil 44.

If the temperature'falls too low, the damper 52 will be moved to full open position and the damper 5| will be moved to full closed position wherefore all of the air leaving the cooling coils will be reheated before being delivered to the rooms or spaces l and II.

If the temperature of the air passing through the discharge duct 2 l5 should rise above the particular control point of the thermostat 219, then the main operating shaft 235 of the motor mechanism 2|8 will move in the opposite direction and first moves switch arm 240 into engagement with contact 24!. This will establish an energizing circuit for \the electrically operable valve 40 and a low-speed circuit for the three-speed control box 232. Such circuits may already be completed by the motor mechanism 211 if the relative humidity is high, but if the relative humidity is low at such time, then these are the only circuits for this valve and three-speed control box. This circuit is as follows: line wire 422,- manual switch 424, wire 421, wire 430, mercury switch 6, wire 43I, wire 434, wire I, switch arm 240, contact 2, wire 442 and wire 436, at which point the circuit branches, one portion going by way of wire 443 to the three-speed control box 232 and wire 444 to ground 425, whereas the other portion goes by way of wire 431, electrically operable valve 40, wire 438, wir 439, and wire- 44!] to ground 425. The compressor again will be operated at low speed, assuming the relative humidity is low, and the refrigerant thus produced will flow through the cooling coil 31. The air passing through the air conditioning device l2 will thereby be cooled and this cooled air will-be delivered to the rooms or spaces l0 and II in proportions determined by the setting of dampers 85 and H0 and the mixture of the air leaving these rooms or spaces passes out the discharge duct 2l5 and over the humidity controller and tern Under these conditions, the damper 5| will again be fully opened and the damper 52 will be completely closed, it being remembered in connection with the description of Fig. 3 that the motor mechanism 2! is so arranged that when it operates its associated switches, the control arm 335 is completely beyond the control resistance 336.

If the temperature of this discharged air should rise further, main operating shaft 235 will rotate to a greater extent in clockwise direction and the operating portion 242 of cam 231 will move switch arm 243 into engagement with contact 244. A circuit for valve 39 and a medium speed circuit for the three-speed control box 232 is thereupon established as follows: line wire 422, manual switch 424, wire 421, wire 439, mercury switch 4l6, wire 43l, wire 434, wire 46!, switch arm 243, contact 244, wire 462 and wire 45l, whereupon the circuit branches, one portion going by way of wire 452 and three-speed control box 232, and wire 444 to ground 425, whereas the other portion goes by way of wire 453, electrically operable valve 39, wire 454, wire 439, and wire 449 to ground 425. The compressor 45 is now operated at a medium speed and part of the refrigerant thus produced flows to me cooling coil 31 and the other portion flows to the cooling coil 36. The temperature of the air being delivered to the rooms Ill and II is thereby further reduced in an effort to lower the temperature of the mixture of air discharged therefrom. If this temperature should rise even higher, main operating shaft 235 will move to its extreme position as the result of clockwise rotation and operating portion 245 of cam 238 will move switch arm 246 into engagement with contact 241 to energize; electrically operable valve 38 and set up a high speed circuit to the three-speed control box 232. This circuit is as follows: line wire 422, manual switch 424, wire 421, wire 430, mercury switch 4l6, wire 43!, wire 434, wire 463, switch arm 2 46, contact 241, wire 464, and wire 451, whereupon the circuit branches, one portion goingby way of wire 458, three-speed control box 232, and wire 444 to ground 425, whereas the other portion goes by way of wire 459, electrically operable valve 38, wire 460 and wire 440 to ground 425. The compressor now operates at high speed and the large quantity of refrigerant thus produced flows to all three cooling coils 35, 36 and 31 to further reduce the temperature of the air passing thereover.

In this manner, during warm weather, the temperature and the relative humidity of the mixture of air being discharged from the rooms or spaces i9 and I I control the flow of refrigerant to the three cooling coils 35, 36 and 31, If the temperature becomes too high, more and-more cooling takes place without any possibility of reheating. Also, as the relative humidity increases, more and more cooling takes place but in the event such cooling causes a lowering of the temperature below the desired amount, then reheating takes place by passing the cooled air over a reheating coil which is heated by the hot gaseous refrigerant being delivered by the compressor 45. The two thermostats H1 and H8 which respectively respond to the temperatures of the rooms I 0 and II control the dampers and I ill, in the manner set forth above, to divide the. cooled air between these two rooms in such a manner as to maintain the two rooms at equal temperatures. It will be apparent that if one or both of these rooms is subjected to a relatively heavy load, then the temperature of the resulting mixture of air leaving both of these rooms will increase wherefore the thermostatic control 219 responsive to such mixed air temperature will cause a greater cooling effect to take place.

In addition, the outdoor compensating control 30 varies the operating point of the main control 219 which responds to the temperature of the mixture of discharged air. Now as the outdoor temperature goes up, the control point of this main control thermostat 219 will be raised wherefore less cooling will be supplied to the air conditioning device l2 for the same discharged air temperature. This means that only a certain amount of cooling can be obtained under'such conditions and this cooling effect is split up between the two rooms l0 and H in accordance with the thermostats located therein so that these two rooms are maintained at equal temperatures. If the outdoor temperature should new fall to say 70 F., the thermostat 4lll will cause mercury switch 6 to open. Opening of this mercury switch breaks the circuit to all of the valves 38, 39 and 40 and also interrupts all of the circuits to the three-speed control box 232. It will therefore be impossible to open any of these valves or -to operate the compressor 46 regardless of the less of temperature fluctuations in the two rooms or spaces Ill and II. The dampers 85 and H therefore remain in half open position irrespective of the temperature in these rooms. The apparatus is now operating on or is ready to operate on a heating cycle and the temperature of the discharged air in the duct 2l5 will undoubtedly fall below 75 F. The thermostat'2'l9 will therefore cause the motor mechanism 2l8 to run to its extreme position in which control arm 335 engases the upper end of control resistance 333 wherefore damper 52 will be moved to full open position and damper 5| will be fully closed. This causes all of the air leaving the air conditioning device l2 to pass through the reheating chamber 43 and over the reheating coil 44. However, since the compressor motor 46 cannot be deenergized by reason of the opening of mercury switch 6, the position of dampers iii and 52 is immaterial in the operation of the system under this heating cycle. Also, although the relative humidity of the discharged air may fluctuate so as to variably position the motor mechanism 2H and operate its switches, as mentioned above, all of the circuits for the valves and the compressor motor are interrupted by opemng of mercury switch 6.

The fresh air at approximately '7 0 F. will there- 'fore pass through the air conditioning device l2 and be delivered in equal portions to the rooms or spaces I0 and II. If this air temperature should be too low'so that the temperature of either of these rooms becomes too low, its thermostat will operate its associated motor mechanism II or 98 to position the corresponding valves 66 and 93 whereby to supply heating fluid to the associated auxiliary heating coils 65 or 92.

If the temperature of the outside air falls below 50 F., then the valve 363 will be opened by the circuit set forth above, and a medium quantity of heating fluid will flow to the preheating coil 2|. The thermostat 395 now becomes operative to position the inlet mixing dampers 22.

and 23 in accordance with the temperature of the air being supplied to the delivery duct l5 so as .to cause a sufiicient quantity of this fresh air to pass through the preheating chamber l9 and over the preheating coil 2| to maintain the temperature of th delivered air at approximately 60 F. The remaining heating of this air will then be accomplished by the individual or auxiliary heating coils 65 and 92 which are controlled by their respective rooms or space thermostats. If the outdoor temperature continues to fall, and falls below 30 F., then the valve 365 is opened eration system including a heating coil and a cooling coil, means to pass said air over said, cooling coil and then over said heating coil prior responsive to the temperature of the air leaving so as to supply a full amount of heating fluid which heating, cooling, and dehumi'dification is obtained and one'which has particular utility forcontr'o'lling thcbnditions'in a plurality of rooms or'spac'es which it is desired to separately 1 control; It will befevid ent that 'many'changesb carrbe made in the details of, the arrangements specifically se't'forth herein and in various 'offth'l sub-combinations without departing from the j r spirit of the present invention, and' I am therefore to "be limited only by the scope'of cliiliins appended hereto. '7: I IJcIaim asmy inve'ntion:

1. An air conditioning system fora plurality of spaces, comprising, in combinatiommeans to'de-- liver. airzto all of said spaces, a-mechanical reirig-= Ic-tu're between said spaces;

all of said spaces in control of the efiect of said heating coil, means to determine the proportions of conditioned air delivered to each of said spaces, and means responsive to the temperature of each or said spaces conjointly controlling said air proportioning means to proportion th air to said spaces in a manner to maintain the temperature of all of said spaces substantially equal.

2. An air conditioning system for a plurality of spaces, comprising, in combination, means to deliver air to all of said spaces, a mechanical refrigeration system including a heating coil and a cooling coil, means to pass said air over said cooling coil and then over said heating coil prior to delivery to said spaces, means responsive to the moisture in a mixture of air from all of said spaces in control of said refrigerating system, damper means in control of the proportions of the air passing over and around said heating colil, means responsive to the temperature of a mixture of air irom all of said spaces in control of said damper means, damper means in control of the flow of the conditioned air to each of the spaces, and means responsive to the temperature in each space in control of said last-named damper means. a

3. An air conditioning system for a pluralit of spaces, comprising,- in combination, an air conditioning device, a plurality of cooling coils therein, valve means to selectively render said cooling coils operative, a mechanical refrigeration system including said cooling coils and a heating means for the air conditioning device which obtains its heat from said mechanical refrigeration system, means to pass air through the air conditioning device and to all of said spaces, means responsive to the moisture content of a mixture of air taken from all of said spaces to operate said valve means to progressively render said cooling coils operative as the moisture content increases, means responsive to a mixture of air taken from "all of said spaces in control of said valve means and heating means to render the heating means operative upon a fall in such temperature and to progressively render said cooling coils operative upon a rise in such temperature, means to determine the proportions of air delivered from the air conditioning device to each of said spaces, and means responsive to the temperature of each space in control of said air proportioning means.

4. In an air conditioning system, in combination, means for supplying-air to a plurality of spaces to be controlled, meansfor cooling the air supplied to saidspaces, flowcontrol ,means forv determining theproportions of the air, passed to i l a a e mos at c m r n v to t temperature of, the air in ,each space for coni trOlling said'flow control means, said thermom m a e ne rrneedtq n o said= flow ntr meats. n i man a ma e i th ,ild il i e llowin a the; space' "temperature maintained to ya'ry, and. 'nsa iu tedv l e mela ne m a s i on of operation for positioning said flowfcontrollingl mean'sjin aImannen-to'c'aiuse'the' delivery of a' predetermined' substantial portion of airto each egardless of the difference in'tempera pastu s n an s a e space 5. In an air conditioning system, in combination, means for supplying air to a plurality of spaces to be controlled, flow varyingmeans for varying the proportions of air supplied to said spaces, means for cooling the air supplied to said spaces, temperature responsive means in each of said spaces, means actuated when the cooling means is in operation for conditioning said temperature responsive means to vary the air delivery to said spaces in a manner to maintain equal temperatures in said spaces while allowing the temperature maintained to vary, means for heating the air supplied to said spaces, and means actuated when the heating means is in operation for controlling said flow varying means so as to cause delivery of predetermined supplies of air to said spaces irrespective of difference in temperature between said spaces.

6. In a heating and cooling system, in combination, means for distributing a stream of air to a plurality of spaces to be conditioned, damper means for determining the proportions of the air stream delivered to each of said spaces, cooling means for cooling said air stream, individual heating means for heating the air delivered to each of said spaces, temperature responsive means in each of said spaces for controlling said damper means, means actuated upon a demand for cooling of said spaces for placing said cooling means in operation and for conditioning said thermostatic means to control said damper means in a manner to maintain equal temperatures in said spaces while permitting variation in such temperatures, means actuated upon demand for heating in said spaces for positioning said damper meansto deliver predetermined supplies of air to said spaces irrespective of temperature difference between said spaces, and individual thermostats in said zones for controlling respective individual heating means.

7. In a summer-winter air conditioning system, in combination, duct means for distributing a stream of air to a plurality of spaces to be conditioned, means for cooling the air stream, individual heating devices for heating the air flowing to each space, means for placing said individual heating means in operation under the control of individual space temperature responsive means when the system is operating on the winter cycle, means for placing said cooling means in operation when the system is operating on the summer cycle, damper means for each space for controlling the amount of air delivered thereto, thermostatic means responsive to the temperature of each space, means for placing said thermostatic means in control of said damper means when the system is operating" on the summer cycle for thereby varying the positions of said damper means in accordance with changes in space temperature during the summer cycle, and means for causing each of said damper means to be run to a predetermined open position when the system is placed on the winter cycle for thereby maintaining a flow of air through said individual heating means to enable said heating means to heat said spaces.

8. In an air conditioning system for a plurality of spaces, the combination of a refrigerating circuit having an evaporator, and means for circulating air to be conditioned thereover and to said spaces, said circuit serving to absorb heat from air being conditioned through said evaporator and reject suchheat; means responsive to relative humidity causing the operation of said circuit to establish a desired relative humidity;

means responsive to reduction of temperature of conditioned air below a limiting temperature for causing the circuit to deliver rejected heat to the conditioned air; means responsive to outdoor temperature for varying said limiting temperature, means to determine the proportions of conditioned air delivered to each of said spaces; and means responsive to the temperature of each of said spaces conjointly controlling said air proportioning means to maintain a predetermined relation between the temperatures of said spaces.

9. In an air conditioning system for a plurality of spaces, the combination of a refrigerating circuit having an evaporator, and means for circulating air to be conditioned thereover and to said spaces, said circuit serving to absorb heat from air being conditioned through said evaporator and reject said heat; means responsive to temperature of air in the conditioned space; means responsive to humidity of air in the conditioned space; means controlled by thetemperature and humidity responsive means for keeping said circuit in operation if temperature or humidity or both be above desired values; means controlled by the temperature responsive means to cause the circuit when operating to reject heat to the conditioned air if the temperature thereof falls below a limiting temperature lower than that at which the temperature responsive means causes operation of the circuit; means responsive to outdoor temperatures to vary said limiting temperature,

means to determine the proportions of conditioned air delivered to each of said spaces; and

.means responsive to the temperature of each of said spaces conjointly controlling said air proportioning means to maintain a predetermined relation between the temperatures of said spaces.

10. In an air conditioning system for an enclosure having a plurality of zones, in combination, air conditioning apparatus, means for passing air through said conditioning apparatus to said zones, damper means for controlling the flow of conditioned air to said zones, electrically controlled motor means for positioning said damper means, thermostatic means in each of said zones, a control circuit for said motor means andineluding said thermostatic means whereby said dampers are positioned in accordance with the temperatures in said zones, said control circuit being operative upon the thermostatic means of one zone being subjected to a change in temperature in a predetermined direction to cause a reduction in the air delivered to the rest of said enclosure, a thermostatic control circuit for said conditioning apparatus, and means associated with said motor means for causing said damper means to assume a position in which air is admitted to all of said zones when said control circuit for said conditioning apparatus is not calling for operation of the conditioning apparatus.

11. In an air conditioning system for an enclosure having a plurality of zones, in combination, air conditioning apparatus, means including a duct leading to each zone for conveying air through said conditioning apparatus to said zones, a damper associated with each zone duct for regulating the flow of air to that zone, an electrically controlled damper motor associated with each of said dampers, thermostatic means in each of said zones, a control circuit for all of said damper motors and including all of said thermostatic means whereby said thermostatic means cooperate in the positioning of said damper motor, said control circuit being operative upon jected to a change in temperature in a predetermined direction tc cause a reduction in the air delivered to the rest of said enclosure, 2. thermostatic control circuit for said conditioning apparatus, and means associated with said motors for causing said dampers to assume positions in which air is admitted to all of said zones when said control circuit for said conditioning apparatus is not calling for operation of the conditioning apparatus.

12. In a system of the class described, in combination, a plurality of zones, means for passing a stream of conditioning fluid to said zones, adjustable distributing means for dividing said stream into individual streams for each zone, electrical motor means for adjusting said distributing means to thereby vary the distribution of conditioning medium to said zones, an electrically operated controller for said motor means and operative to selectively cause movement of said distributing means in either direction, a first condition responsive variable impedance responsive to the condition at one of said zones for controlling and second condition responsive variable impedances in controlling the energization of said controller and hence the position of said motor means.

' JOHN E. HAINES. 

